Caching Android ndk fails with permission

[daisy1754]

Describe the bug
Since Android NDK is not preinstalled (#643), I'm writing custom cache rule:

      - name: NDK Cache
        id: ndk-cache
        uses: actions/cache@v2
        with:
          path: |
            /usr/local/lib/android/sdk/ndk
          key: ndk-cache-21.0.6113669

When github action restores cache, I'm seeing following error:

/bin/tar: ../../../../../usr/local/lib/android/sdk/ndk: Cannot mkdir: Permission denied

Area for Triage: Android

Question, Bug, or Feature?: Feature

Virtual environments affected

• macOS 10.15
• Ubuntu 16.04 LTS
• Ubuntu 18.04 LTS
• Ubuntu 20.04 LTS
• Windows Server 2016 R2
• Windows Server 2019

Expected behavior
setting proper permission to /usr/local/lib/android/sdk/ndk so it can be cached

Actual behavior
cache restoring fails with permission issue

[htbkoo]

Not sure if this would help / is a good idea, but I had tried to work around it by adding this follow step before the NDK cache step:

    - id: fix-ndk-permission
      name: Fix the NDK folder permission to allow caching
      shell: bash
      run: |
        sudo mkdir ${ANDROID_HOME}/ndk
        sudo chmod -R a+rwx ${ANDROID_HOME}/ndk

TL;DR: I had tried to create the ndk folder under ${ANDROID_HOME} manually and grant a 777 permission to all

But yea I admit this seems to be hacky and it would be great if the team can fix it in a more proper way / enable NDK caching by default

[maxim-lobanov]

Hello everyone,
We would like to get additional discussion with actions/cache team because fix from image side doesn't look good from long term perspective.

Just to summarize context of problem:

1. Folder /usr/local/lib/android/sdk/ndk doesn't exist on image by default
2. Root permissions are set for whole /usr/local directory and it is available only with sudo (it is expected for Linux images)
3. Repro steps:

• User runs sudo /usr/local/lib/android/sdk/tools/bin/sdkmanager --install "ndk;20.0.5594570" (sudo is necessary here because of permissions)
• User cache this directory /usr/local/lib/android/sdk/ndk that is created by first command
• actions/cache can't restore this folder because it doesn't use sudo

Workaround:
Add before cache step:

sudo mkdir ${ANDROID_HOME}/ndk
sudo chmod -R a+rwx ${ANDROID_HOME}/ndk

Solution

As a solution, we can create /usr/local/lib/android/sdk/ndk folder on image and set proper permissions for whole /usr/local/lib/android folder. And this solution will resolve this particular issue. But the root cause is deeper and I anticipate more issues in future with other tools and same root cause.
Simple example:

runs-on: ubuntu-latest
steps:
- uses: actions/cache@v2.1.0
  with:
    path: /usr/local/my_awesome_tool 
    key: mykey
- name: Install awesome tool
  run: |
    sudo mkdir /usr/local/my_awesome_tool
    echo "binary file is here" | sudo tee -a /usr/local/my_awesome_tool/binary

This example shows that any other customer can face with the same issue with any other tool and actions/cache.
How can we help customer with this case? I don't think that setting user permissions on the whole /usr/local folder (or even whole machine) is good idea.

I understand position of actions/cache owners that action shouldn't use sudo tar everywhere because it could cause problems on self-hosted machines. But may be we could find better way to handle it.
@joshmgross, what do you think about it?

[nikita-bykov]

We have merged the PR that sets proper permissions for whole /usr/local/lib/android folder. Images with changes will be rolled out around next week.

[nikita-bykov]

All changes were successfully deployed.

[maxim-lobanov]

Reopened issue since caching still doesn't work properly for some components
cc: @dmitry-shibanov to take a look

[dmitry-shibanov]

Hello, we merged new fix for permissions. Changes will be added in next images rollout.

[dmitry-shibanov]

Hello, changes were added. If you have any concerns feel free to reopen the issue.